The present invention relates to a novel method and apparatus for detecting the condition of combustion in an internal combustion engine and it relates to a crank angle sense to be used in the apparatus. Further, it relates to an internal engine control method and apparatus using the first-mentioned method and apparatus.
In a conventional apparatus, as described in Japanese Patent Unexamined Publication No. Sho-58-51243, the revolution speed of an internal combustion engine is detected at least two points within one ignition cycle from a preceding ignition point of time to a succeeding ignition point of time, the value of variation in the revolution speed within that one ignition cycle is calculated based on the difference in revolution speed between the two points, and the value of variation in the revolution speed calculated successively is subject to statistically operational processing to thereby judge the condition of combustion in the internal combustion engine.
The aforementioned conventional technique has no consideration for judgment of of the degree of the combustion condition. There arises a problem in that no judgment can be made except the judgment as to whether the condition of combustion is normal or not.
Further, the aforementioned conventional technique has no consideration for disadvantages caused by the statistically operational processing. There arises a problem in that accuracy in detection is poor and in that the processing speed is too low to detect the condition of combustion in a timely manner.